4.12 Greenhouse Effect

a) UV Light from the sun - short wavelength or high energy
b) 50% of the light is reflected back out into space the main cause of this are things like clouds
c) Absorption on the outer surface where the UV Light is converted and emitted as Infrared
d) Infrared light - long wave
e) Space - heat
f) Greenhouse gasses - water vapour, CO2, CH4 etc.
- the infrared light hits the greenhouse gas
- it will absorb the energy and then re-emitts it in all directions (including downwards) = re-emitts infrared and re-distributes
- some of the gasses which goes downwards to the surface raises the surface temperature a little bit higher

Enhanced greenhouse effect:
- if we raise level of pollution gasses, they will absorb more of the infrared radiation and emits it backwards towards the earth making the temperature higher = leading to climate change

CFC:
- known for their effect on ozone layer
- 03
- CCl3F ----(sunlight)---> CCL2F- + Cl-
- catalyses the breakdown of O3 into O2
- O3 is better at absorbing UV Light than O2